Comparison of gallium-67 citrate and technetium-99m glucoheptonate in the evaluation of pulmonary malignancies.

Sixty-five patients with suspected or proven pulmonary malignancy were examined with [67Ga]citrate and [99mTc]glucoheptonate ([99mTc]GH) scintigraphy. In the final diagnosis 39 had primary lung carcinoma, four metastases in lung, mediastinum, and pleura from carcinomas elsewhere, and 22 benign pulmonary diseases. The sensitivity in the detection of pulmonary malignancies was 91% with 67Ga and 95% with [99mTc]GH. The intensity of uptake was somewhat greater with 67Ga than with [99mTc]GH in almost all malignant lung tumor groups. The specificity to detect malignant tumors was 82% with both radiopharmaceuticals. Irradiation and chemotherapy seemed to decrease 67Ga uptake but not [99mTc]GH uptake. Only four of 22 benign diseases showed accumulation of both 67Ga and [99mTc]GH. The intensity of uptake in benign processes was almost equal with that in malignant diseases, but most malignant processes were better delineated than the benign lesions. There were many differences between 67Ga and [99mTc]GH uptake, which suggest different mechanisms of accumulation of these agents. It is concluded that some 67Ga studies could be replaced by cheaper and more practical [99mTc]GH.